- Durham University
Department of Geography
South Road
Durham DH1 3LE
UK - 00441913341894
Nikolaos Galiatsatos
Durham University, Geography, Faculty Member
- Durham University, Archaeology, Post-Docadd
- Spatial Modeling, Remote Sensing, Digital Photogrammetry applied to Archaeology, Multidisciplinary, Uncertainty Quantification, Research Data Management, and 7 morePhotogrammetry, Archaeology, Geography, Geographic Information Systems (GIS), Anthropology, Environmental Sustainability, and Landscape Archaeologyedit
Research Interests:
Research Interests:
ABSTRACT We developed the technology of microslice integral field units some years ago as the next step in SAURON type microlens IFU design with typically 5 times more spatial elements (spaxels) for the same spectrograph and spectral... more
ABSTRACT We developed the technology of microslice integral field units some years ago as the next step in SAURON type microlens IFU design with typically 5 times more spatial elements (spaxels) for the same spectrograph and spectral length aiming at 1,000,000 spaxels IFUs. A full instrument for laboratory demonstration composed of the fore-optics, the IFU, the spectrograph and the detector has now been built and tested. It has about 10,000 spatial elements and spectra 150 pixel long. Our IFU has 5 cylindrical microlens arrays along the optical axis as opposed to one hexagonal array in the previous design. Instead of imaging pupils on the spectrograph input focal plane, our IFU images short slitlets 17 pixel long that keep the spatial information along the spatial direction then giving 17 spaxels per slitlet instead of one in pupil imaging. This removes most of the lost space between spectra leaving place for more and keeps the spatial information over the element size while pupil images lose it. The fore-optics re-images the field on the input of the IFU. They are made of cylindrical optics to get the desired different magnifications in both directions. All the optics and detector fit in a cylinder 35 mm in diameter and 280 mm long. With a different set of fore-optics on a 4-m telescope, a field of 43" x 6.7" with spatial elements of 0.14" x 0.22" could be observed so 12 of these mini-spectrographs would cover a field surface area of about 1 arcmin2 and 120,000 spaxels.
Research Interests:
Research Interests:
ABSTRACT: Remote sensing is a well established technique that has been employed in archaeological research for nearly a century. Until recently the technique was limited to site specific aerial photography focused solely in the visual and... more
ABSTRACT: Remote sensing is a well established technique that has been employed in archaeological research for nearly a century. Until recently the technique was limited to site specific aerial photography focused solely in the visual and near infra-red components of the electromagnetic spectrum. Improvements in sensor technology mean that archaeologists can exploit remotely sensed imagery from different electromagnetic wavelengths and platforms. This has the potential to increase the area of study and extend the window of ...
Research Interests:
The first space mission to provide stereoscopic imagery of the Earth’s surface was from the American CORONA spy satellite program from which it is possible to generate Digital Elevation Models (DEMs). CORONA imagery and derived DEMs are... more
The first space mission to provide stereoscopic imagery of the Earth’s surface was from the American CORONA spy satellite program from which it is possible to generate Digital Elevation Models (DEMs). CORONA imagery and derived DEMs are of most value in areas where conventional topographic maps are of poor quality, but the problem has been that until recently, it was difficult to assess their accuracy. This paper presents a methodology to create a high quality DEM from CORONA imagery using horizontal ground control derived from Ikonos space imagery and vertical ground control from map-based contour lines. Such DEMs can be produced without the need for field-based ground control measurements which is an advantage in many parts of world where ground surveying is difficult. Knowledge of CORONA image distortions, satellite geometry, ground resolution, and film scanning are important factors that can affect the DEM extraction process. A study area in Syria is used to demonstrate the method, and Shuttle Radar Topography Mission (SRTM) data is used to perform quantitative and qualitative accuracy assessment of the automatically extracted DEM. The SRTM data has enormous importance for validating the quality of CORONA DEMs, and so, unlocking the potential of a largely untapped part of the archive. We conclude that CORONA data can produce unbiased, high-resolution DEM data which may be valuable for researchers working in countries where topographic data is difficult to obtain.
Research Interests:
Research Interests:
Research Interests:
This paper aims to investigate the applicability of a relative radiometric normalisation method to a set of multitemporal images acquired by sensors of substantially different characteristics. The overall aim of the project is to assess... more
This paper aims to investigate the applicability of a relative radiometric normalisation method to a set of multitemporal images acquired by sensors of substantially different characteristics. The overall aim of the project is to assess the potential of satellite remote sensing for identifying forest land cover change in Scotland. In this study, the Pseudo-Invariant Features (PIFs) concept was investigated. PIFs
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Research Interests:
Research Interests:
Research Interests:
Here we illustrate a ground map approach that uses orthorectified CORONA KH4B images and declassified topographical maps to study historical land-use dynamics and to help planning archaeological survey in the monsoonal semi-arid alluvial... more
Here we illustrate a ground map approach that uses orthorectified CORONA KH4B images and declassified topographical maps to study historical land-use dynamics and to help planning archaeological survey in the monsoonal semi-arid alluvial plains of North Gujarat, India. In spite of its generalized use in archaeological applications, CORONA photographs have rarely been used in Indian archaeological contexts. The methods discuss a cost-effective and integrated protocol for: (i) obtaining ground control points (GCPs) and orthorectify CORONA photographs when very high-resolution imagery or detailed topographic maps are not available; and (ii) evaluating the integration of declassified datasets into Google Earth Pro for addressing archaeological surveys in remote areas. The merging of CORONA imagery with declassified USA and the former USSR historical military maps provided a picture of the human–environment interaction in North Gujarat of the past 40 years, prior to the intense development of mechanical agriculture and regional irrigation channels. We conclude by identifying the human and climate-induced taphonomical processes that are obliterating a fragile landscape characterized by archaeological scatters located in fossilized sand dunes.